Zend\Mvc\MvcEvent::getViewModel PHP Method

    public function getViewModel()
    {
        if (null === $this->viewModel) {
            $this->setViewModel(new ViewModel());
        }
        return $this->viewModel;
    }

 /**
  * Add the ACL of this module to the global ACL
  *
  * @param MvcEvent $e 
  * @return void
  */
 public function initAcl(MvcEvent $e)
 {
     if ($e->getViewModel()->acl == null) {
         $acl = new Acl();
     } else {
         $acl = $e->getViewModel()->acl;
     }
     $aclConfig = (include __DIR__ . '/config/module.acl.php');
     $allResources = array();
     foreach ($aclConfig['roles'] as $role) {
         if (!$acl->hasRole($role)) {
             $role = new Role($role);
             $acl->addRole($role);
         } else {
             $role = $acl->getRole($role);
         }
         if (array_key_exists($role->getRoleId(), $aclConfig['permissions'])) {
             foreach ($aclConfig['permissions'][$role->getRoleId()] as $resource) {
                 if (!$acl->hasResource($resource)) {
                     $acl->addResource(new Resource($resource));
                 }
                 $acl->allow($role, $resource);
             }
         }
     }
     $e->getViewModel()->acl = $acl;
 }